Question: Jessica starts counting at 42, and she counts by fives. If 42 is the 1st number that Jessica counts. what is the 8th number that she counts?
Solution: What is the first number that she counts? $42$ What is the second number that she counts? $\begin{align*}&42 + 5 \\ &= 47\end{align*}$ What is the third number that she counts? $\begin{align*}&42 + 5 + 5 \\ &= 42 + (2 \times 5) \\ &= 52\end{align*}$ What is the 8th number that she counts? $\begin{align*}&42 + (7\times5) \\ &= 42 + 35 \\ &= 77\end{align*}$